Bottle base



FIG. 1 is a bottom, right side perspective view of a bottle base showing my new design;

FIG. 2 is a bottom, left side perspective view thereof;

FIG. 3 is an alternate bottom perspective view thereof;

FIG. 4 is an alternate bottom perspective view thereof;

FIG. 5 is a bottom plan view thereof; and,

FIG. 6 is a side elevational view thereof.

The broken lines shown in the drawings are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a bottle base, as shown and described. 